Overlay for cathode ray tube display

• US 4,562,481 A
• Filed: 09/30/1982
• Issued: 12/31/1985
• Est. Priority Date: 09/30/1982
• Status: Expired due to Fees

• Current Assignee: Datapoint Corp. (Dynacore Holdings Corporation)
• Original Assignee: Datapoint Corp. (Dynacore Holdings Corporation)
• Inventors: Trakas, Theodore C.
• Primary Examiner(s): Martin, John C.
• Assistant Examiner(s): Coles, Edward L.
• Application Number:
  US06/430,935
• Time in Patent Office: 1,188 Days
• Field of Search: 358/231, 358/247, 358/250, 358/251, 358/252, 358/253, 350/276-282, 313/474
• US Class Current: 348/834
• CPC Class Codes: H04N 5/72 Modifying the appearance of television pictures by optical filters or diffusing screens

Abstract

The disclosed CRT overlay, which is mounted to the display face of a CRT, comprises an overlay panel (typically a non-glare optical filter) mounted at its edges to the CRT display face and a layer of transparent glass beads interposed between the overlay panel and the CRT display face. The glass beads maintain a thin (in the range of 0.005 inches or less) gap between the overlay panel and the display face, such that display clarity is substantially unaffected by the mounting of the overlay panel. The use of the glass beads enables the overlay panel to be mounted without a relatively expensive bonding process, while at the same time avoiding the display clarity degredation associated with currently employed air-gap mounting techniques.

Claims

1. An overlay for the display face of a CRT comprising:

(a) An overlay panel conforming in contour to the CRT display face, and disposed in laminal, spaced relation to the display face;

(b) Transparent, rigid, substantially spherical particles of a predetermined size interposed between said overlay panel and the CRT display face such that a substantially uniform gap is maintained between them; and

(c) Means for securing the edges of said overlay panel to the CRT display face.

2. A CRT overlay as defined in claim 1 wherein said transparent particles are of substantially spherical shape.

3. A CRT overlay as defined in claim 2 wherein said overlay panel comprises an optical filter having a glare-reducing exterior matt finish.

4. A CRT overlay as defined in claim 3 wherein said transparent particles comprise glass substantially spherically shaped beads.

5. A CRT overlay as defined in claim 4 wherein said securing means comprises strips of double-sided adhesive secured adjacent the edges of either said overlay panel or the CRT display face.

6. A CRT overlay as defined in claim 5 wherein said glass spheres are substantially the same as Spheriglass #3000 glass beads (45 micron) manufactured by Potter Industries.